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A series of gas sensing layers based on indium oxide doped with gold were prepared by using the aerosol technology for deposition as the active contact layer in a metal oxide semiconductor capacitive device. The interaction between the measured species and the insulator surface was quantified as the voltage changes at a constant capacitance of the device. The sensor properties were investigated in the presence of H 2 , CO, NH 3 , NO, NO 2 and C 3 H 6 at temperatures between 100-400°C. Significant differences in the morphology of the layer and its sensitivity were noted for different preparation methods and different gas environments.

In this work the effect of ambient influence on the electrical conductivity of ZnO films has been studied. Nanostructured ZnO films (undoped and Ga, Co, Mn doped) were exposed to oxygen (1 -80 vol. %) at temperature range 300 -500 ºС. A dominant effect of ambient influence via oxygen absorption was observed: the intensity of conductivity decrease was found to be proportional with temperature and tends to saturation with time. After oxygen saturation the reversible effect of oxygen adsorption became dominant and contributed to the films conductivity. Oxygen exposed undoped ZnO films revealed high sensitivity for oxygen content change in the ambience, therefore they have been further processed for gas sensor fabrication.

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Abstract-High frequency measurements at 50 MHz-10 GHz were performed for the first time using interdigitated electrodes on a low temperature co-fired ceramic substrate to analyze fungal spores. Wet and dry spore generation methods were evaluated and tested with two different fungal species. The dry generation method was found feasible for RF measurements, since the component capacitance increased 14-21% in the 2-6 GHz range, but for the wet generation method the capacitance decreased only slightly (< 1%). Based on these initial results the RF measurements have the capacity to evaluate the quantity of fungal spores but not to identify their species.